David writes:

> Jim< while I am not that familiar with the wasserboxer setup, a common
> source of a cold interior is a faulty, plugged heater core matrix.

I greatly boosted the heat output of my '85 by "boiling out" the 2 
heater cores with that powdered cleaner prestone makes (2 part stuff, you 
finish with a neutralizer).  BUT I rigged up a pump and boiling keg 
to circulate the caustic solution so none of it went thru my engine.  
I left this boil (I used a 170,000 BTU propane cooker) and circulate 
2 hours and flushed it.  Ahhhh.... heat.

> What we do up here is
> cover the grille area (cardboard etc) but I have no idea what effect this
> would have with the engine at the back;

We do that 'down' here too!  I just put on the cardboard this 
weekend.  This is what I THINK it does... I just 'feel better' 
knowing its on!  With the cardboard in front, the radiator actually 
returns warm coolant vs the frigid stuff from the ambient temp.  I 
feel better introducing warm coolant to a hot engine than freezing 
cold.  Here's one thing that ISN'T subjective:  I make the cardboard 
tall enough to cover the fresh air intake grill for the interior.  
Without this, so much fresh air is pushed in at highway speed that it 
overloads the heater core and it blows cool air.  Also, run with your 
front heater fan in the 1 or 2 position for the hottest air.  Run the 
back one on full blast because it's essentially re-using warmed 
interior air anyway.